The present invention relates to portable, handheld and wearable detector systems and in particular to portable, handheld and wearable detector systems including sensor arrays configured for non-specific chemical analyte detection, and which are configurable with software modules to detect and analyze a variety of environmental conditions and which have low operating power requirements and long lifetimes.
Civilian and military personnel, Coast Guard and Customs, State and Federal Emergency Responders, and Industrial Workers need a personal early-warning system to identify changes in environmental conditions, such as the release of hazardous airborne chemicals, in time to either evacuate or don protective equipment, such as chemical protective equipment (CPE). For example, releases of toxic industrial chemicals (TICs) may occur accidentally in the course of normal operations, from unseen leaks in fueling, heating or cooling systems, or from intentional hostile actions. Additionally, chemical warfare agents (CWAs) may be released during combat or in other potentially hostile situations. Each of these situations presents a unique and potentially broad range of chemical threats that typically cannot be identified a priori. There is a need to detect and characterize TICs, CWAs, and other environmental conditions before hostile exposure in order to take appropriate actions to neutralize the threat. A similar need exists after a TIC or CWA release to identify the chemical agent class such that appropriate defensive and decontamination measures may be taken.
While laboratory instruments with high specificity and accuracy are available, they are not generally suitable for field use because they lack physical robustness, require highly trained operators, and typically are not portable due to size, weight, high power consumption requirements, and chemical reagent (gases, liquids) requirements. In addition, specialized portable instruments for one threat type, (e.g. CWA) may not work for the other threat types of interest, (e.g. explosives, fire or TICs) or for improvised devices.
Handheld as well as wearable, passive detectors for hazardous conditions such as TICs and CWAs will greatly improve the safety of the personnel operating in threatened environments. Useful known portable detectors include point detectors and standoff detectors. One point detector, the Joint Chemical Agent Detector (JCAD), is hand held and portable but has a limited operational life on a single charge, requiring frequent recharging. In addition, the JCAD has to be handled impairing use of other devices simultaneously. Standoff detectors, such as the Joint Services Lightweight Standoff Chemical Agent Detector (JSLSCAD), can continuously protect personnel from CWAs, but (1) lack spatial resolution and (2) have detection limits much larger than the Immediately Dangerous to Health and Life (IDLH) level. General limitations of current badge or wearable detectors (e.g., SafeAir, ToxiRAE) include: 1) analyte-specificity: these require detailed a priori knowledge of chemical hazards, or multiple badges for broad spectrum coverage, and cannot detect new or unknown hazards; 2) single-use: disposable detectors and dosimeters require re-supply for continuous protection; 3) interpretation errors: calorimetric indicators require visual comparisons (color cards) that are prone to user subjectivity; 4) no alarm modes or communications capability: these do not provide rapid hands-free warning or transmission of status; 5) environmental performance: extremes of temperature (e.g., <0° or >40° C.) and humidity (e.g., <10% or >90% relative humidity (RH)) limit some sensors (e.g., electrochemical, conducting polymers). Such detectors also do not typically include datalogging capability (e.g., storing detailed historical information/records of the environment encountered), or may only provide a time-averaged history of exposure. Additionally, current detectors also typically have high operational power requirements and, therefore, typically short operational lifetimes. For example, the JCAD requires recharging or replacement of the power supply every 20 hours or less.
Some sensor devices, such as the ToxiRae Plus, produce audible and vibratory alarms, eliminate interpretation errors, and have datalogging capability, but these wearable sensors are still analyte-specific. In addition, these sensors are not useful as badge detectors since they require a pocket or belt clip due to their size and weight.
Wearable sensor devices with analyte-general capability have been developed, e.g., by EIC Laboratories, Inc. and Physical Sciences, Inc., however these devices have significant performance issues with humidity that are likely to affect the ruggedness and stability of the sensors during field-use of the badge detector.
There is therefore a need for personal detectors (e.g., portable and wearable detectors) that overcome the limitations of current detectors and which provide personnel with continuous, reliable protection in a potentially dangerous environment.